One type of power-operated device, which operates in a cordless mode, typically includes a housing having a chamber for receiving and retaining a removable, enclosed battery pack in a self-contained fashion. The battery pack, which is mounted within a container, completely encloses batteries or cells contained within the pack and provides the necessary D.C. power for operation of the device. Such devices could include cordless power tools and equipment such as, for example, drills, screwdrivers, screwdriver-drills, hammer-drills, jig saws, circular saws, shears, hedge trimmers, battery-operated household products and any type of cordless powered devices which normally operate in a relatively high power range, for example, above 50 watts. Even though the cordless powered products operate in a relatively high power range, such products typically do not require a powered cooling facility.
On occasions, the operator of a cordless-mode power-operated device, as described above, may be in an area which is readily accessible to a continuous A.C. power source, or a high level D.C. voltage source. It would be most efficient if the operator could use the readily available A.C. source or high level D.C. source and thereby reserve the battery power for use in areas where the A.C. source or high level D.C. source is not available. In such instances, a voltage converter could be used to convert the A.C. voltage or high level D.C. voltage to low level D.C. voltage required to operate the powered device. However, as noted above, a typical high powered cordless device is not designed to provide powered cooling. Therefore, when such a device is powered by a continuously available source, overheating of the motor and other components of the device becomes a concern.
One example of such a voltage converter is described in the above cross-referenced U.S. patent application Ser. No. 07/161,122, entitled "Voltage Converter." Also, one example of using a voltage converter to operate a powered device in the manner noted above is described in the above cross-referenced U.S. patent application Ser. No. 07/160,911, entitled "Dual-Mode Corded/Cordless System For Power-Operated Devices."
Therefore, there exists a need for a facility for operating a low voltage device in a corded mode, while providing powered cooling at least during the corded mode of operation. Also, there is a need for a lightweight facility which can be contained within a low voltage power-operated device for operating the device in a corded mode and with powered cooling without increasing the weight and detracting from the portability of the device. Further, it is imperative that such a facility be contained to operate in an environment which is safe.